A practical guide to choosing a CNC waterjet. Compare pure vs. abrasive, 3-axis vs. 5-axis, and table sizes (2015-4020, custom) for your materials and budget.

Choosing the right CNC waterjet involves matching the machine's axis configuration, cutting mode, and table size to your specific materials, part complexity, and production goals. This guide provides a practical decision map to help you select the optimal setup, whether you're cutting stone countertops, intricate mosaics, or advanced composites.

The core decision points revolve around four key areas: the cutting medium (pure water or abrasive), the number of axes (3 or 5), the physical machine size, and the specific material being processed. Understanding these trade-offs is crucial for maximizing your return on investment.

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Pure Water vs Abrasive Waterjet: Use Cases & Materials

The first fundamental choice is whether you need an abrasive system. This decision is dictated entirely by the materials you plan to cut.

Thin metals, plastics, foams ￫ Pure Water | Stone, sintered slabs, CFRP, glass ￫ Abrasive

  1. Pure Waterjet: Best for soft materials where an abrasive is unnecessary. Examples include foam, rubber, gaskets, thin plastics, and food products. It's faster and cheaper for these applications as it consumes no garnet.

  2. Abrasive Waterjet: Essential for cutting hard materials. The addition of a garnet abrasive to the water stream provides the eroding power needed for stone (granite, marble), metal (steel, aluminum), composites (CFRP), glass, and ceramics. Virtually all stone and countertop work requires an abrasive system.

Axis Choice: 3-Axis vs 5-Axis (Profiles vs Bevels)

The number of axes determines the geometric complexity your machine can handle.

Tight radii & mosaics ￫ 5-Axis | Flat profiles & simple cutouts ￫ 3-Axis

  1. 3-Axis Waterjet: Operates in the X, Y, and Z dimensions. It is perfect for cutting 2D profiles and flat parts. It's a cost-effective solution for shops primarily focused on simple cutouts, straight edges, and basic shapes.

  2. 5-Axis Waterjet: Adds A and B (or A and C) axes, allowing the cutting head to tilt. This enables the creation of beveled edges, countersinks, and complex 3D contours. For countertop fabrication, a 5-Axis CNC Waterjet Machine is critical for creating mitered edges for waterfall countertops and providing taper compensation to ensure perfectly vertical edges on thick materials.

Table Sizes: 2015 / 2515 / 3020 / 4020 / Custom Builds

The table size determines the maximum dimensions of the workpiece you can process.

Footprint vs part size; large patterns ￫ 4020, compact shops ￫ 2015/2515; mixed ￫ 3020

Standard models are often designated by their X and Y travel in millimeters (e.g., a 4020 model has a cutting area of roughly 4000mm x 2000mm). The choice depends on a balance between your available floor space and typical job size.

  1. 2015 / 2515 Models: Ideal for smaller shops, R&D labs, or businesses cutting smaller components.

  2. 3020 Models: A popular, versatile size that accommodates many standard material sheets and is suitable for a wide range of jobs, including most countertops.

  3. 4020 Models: Suited for large-format cutting, such as architectural panels, large floor mosaics, or nesting many smaller parts on a single large slab to maximize material yield.

  4. Custom Builds: For unique requirements, such as extra-long or wide parts, custom-sized tables can be engineered to fit a specific production line or application.

Material-Specific Guidance: Stone, Sintered Slabs, Metals, CFRP, Glass

Your material dictates not just the machine configuration but also the process parameters.

Material

Key Selection Factor

Recommendation

Stone (Granite, Marble)

Intricate shapes, sink cutouts.

First Choice: 5-Axis Abrasive. Allows for bevels and complex contours.

Sintered Slabs

High risk of chipping, very hard.

First Choice: 5-Axis Abrasive with low-pressure piercing. Not Recommended: Pure water or mechanical saws.

Metals (Steel, Aluminum)

Thickness, no HAZ required.

Alternative: 3-Axis Abrasive. Pure water is only an option if the metal is very thin, typically just a few millimeters thick. Superior to plasma/laser for thick parts with no heat distortion.

Composites (CFRP)

Risk of delamination.

First Choice: 5-Axis Abrasive for complex shapes. Requires precise speed and pressure control.

Glass

Extremely brittle.

First Choice: 3-Axis or 5-Axis Abrasive with low-pressure piercing. Not Recommended: High-pressure piercing.

Frequently Asked Questions

When is pure water cutting enough?

Pure water is sufficient only for soft materials like foam, rubber, paper, and certain thin plastics. For any stone, metal, glass, or composite, an abrasive system is required.

Can a 3-axis waterjet handle stone mosaics?

A 3-axis machine can cut the 2D shapes for mosaics, but it cannot create beveled edges for tight, seamless fits. A 5-axis machine is recommended for high-end mosaic work where precision and finish quality are paramount.

Should I choose a 3020 or 4020 table size for my waterjet?

Choose a 4020 if you frequently work with large slabs or want to maximize material yield by nesting many parts. A 3020 offers a good balance for general-purpose work and smaller shops. A 2015 or 2515 is ideal for limited footprints.

What spares should I stock for a new waterjet machine?

Common consumables include nozzles (orifices), mixing tubes (sand tubes), and high-pressure seal kits. Having these on hand is crucial to minimize downtime.

Is a waterjet better than a bridge saw for all stone cutting?

Not necessarily. A bridge saw is often faster for long, straight cuts. A waterjet excels at cutting complex curves, sharp corners, and intricate internal cutouts without risk of cracking—jobs a bridge saw cannot do.